Enhanced decolorization of rhodamine B solution through simultaneous photocatalysis and persulfate activation over Fe/C3N4 photocatalyst

In this study, organic contaminant degradation was intensified by increasing the oxidative capacity of the reaction system through simultaneous photocatalysis and heterogeneous persulfate activation. Fe nanoparticles were served as a multifunctional modifier to enhance the photoactivity of graphitic carbon nitride (CN), by tuning optical properties as well as persulfate (PS) activation rate, by introducing a new activation pathway. The synthesized photocatalysts were characterized by X-ray diffraction (XRD), Fourier transformed infrared spectroscopy (FT-IR), scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), transmission electron microscopy (TEM), UV-visible diffuse reflectance spectroscopy (UV-vis DRS), and photoluminescence (PL) analysis. Oxidation power of the proposed system was examined by the degradation of Rhodamine B (RhB) as a model pollutant under visible light irradiation. The effect of operating parameters contributing to the degradation process, including initial pH, and the concentration of the photocatalyst and potassium persulfate were investigated in detail. Scavenging experiments proved that the photocatalyst hole and sulfate radicals play a major role in RhB degradation, and a plausible mechanism for the generation of oxidative species was proposed. Furthermore, reusability tests revealed that the photocatalysts possess excellent stability after three repetitive experiments. (C) 2019 Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.